medullary cavity

{{short description|Area inside a bone where marrow is stored}}

{{Infobox anatomy

| Name = Medullary Cavity

| Latin = cavitas medullaris

| Image = Structure_of_a_Long_Bone.png

| Caption = A long bone, with medullary cavity labeled near center.

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The medullary cavity (medulla, innermost part) is the central cavity of bone shafts where red bone marrow and/or yellow bone marrow (adipose tissue) is stored; hence, the medullary cavity is also known as the marrow cavity.

Located in the main shaft of a long bone (diaphysis) (consisting mostly of spongy bone), the medullary cavity has walls composed of compact bone (cancellous bone) and is lined with a thin, vascular membrane (endosteum).{{cite book |last1=Martini |first1=F. |last2=Nath |first2=J. L. |year=2009 |title=Fundamentals of Anatomy and Physiology |edition=8th |location=San Francisco, CA |publisher=Pearson Education |isbn=978-0-321-50589-7 }}{{Cite book |last=Tortora |first=Gerard J. |url=http://worldcat.org/oclc/1299321666 |title=Principles of anatomy and physiology |publisher=Wiley |year=2022 |isbn=978-0-7303-9200-2 |oclc=1299321666}}

This area is involved in the formation of red blood cells and white blood cells, and the calcium supply for bird eggshells. The area has been detected in fossil bones despite the fossilization process.

{{Cite journal

| last1 = Peterson | first1 = J. E. | last2 = Lenczewski | first2 = M. E. | last3 = Reed | first3 = P. S.

| title = Influence of Microbial Biofilms on the Preservation of Primary Soft Tissue in Fossil and Extant Archosaurs

| journal = PLOS ONE | volume = 5

| issue = 10

| pages = 13A

| date = October 2010

| doi = 10.1371/journal.pone.0013334

| editor1-last = Stepanova

| editor1-first = Anna | pmid=20967227 | pmc=2953520| bibcode = 2010PLoSO...513334P | doi-access = free }}

Intramedullary is a medical term meaning the inside of a bone. Examples include intramedullary rods used to treat bone fractures in orthopedic surgery and intramedullary tumors occurring in some forms of cancer or benign tumors such as an enchondroma.